1. Field of the Invention
This invention relates, generally, to flexible tubes used for filtration and, more particularly, to flexible filter tubes which are composed of elements which can be disassembled to enable recycling of the still usable elements of the tube and, additionally, to the method of recycling such tubes.
2. Description of the Prior Art
Flexible tube filtration is a well-known and highly valued filtration technique which uses a specialized apparatus. This filtering technique and an early apparatus for accomplishing this technique, were described in U.S. Pat. Nos. 3,100,190 and 3,642,141, both issued to Hobson, and both of which are incorporated by reference into this application.
Developments in the flexible filter tube construction have lead to increased use of monofilament strands which are braided to form the outer jacket of the tubes, in addition to the more traditional stainless steel braiding used to form the outer jacket.
Filter tubes do not, generally, last forever. Some applications, such as the filtration of coolants for grinding of carbide tool bits, cause the filter strands to be eroded, and small holes in the wall result. Leakage of the particles through the wall ensues, and service personnel must correct the condition. Normally, the damaged elements are removed and discarded and new elements installed to replace them.
In order to minimize down time for the filtering apparatus due to ad hoc replacement of individual filter elements as they fail, many customers routinely replace all their tubes in accordance with a maintenance schedule. Some filters have over a thousand tubes, each of which tube contains stainless steel components such as the internal shaping spring. Yet the whole tube will be discarded, though the only part of the tube that needed replacement was the outer jacket. The springs are rarely ever damaged, and can be recycled almost without limit.